I recently watched two interviews with OpenAI researchers where they describe that the breakthrough of o-series (unlike GPT series) is to focus on test time compute as they are designed to “think” more specifically to avoid pattern matching. Noam Brown https://youtu.be/OoL8K_AFqkw?si=ocIS0YDXLvaX9Xb6&t=195 and Mark Chen https://youtu.be/kO192K7_FaQ?si=moWiwYChj65osLGy